I first came across with respect to Charlie Houston's K2 1953 expedition, when the climbers worked together to try to rescue Art Gilkey who was suffering from a blood clot in the leg. Th rescue was a great act of heroism on the part of the climbers, and in particular on the part of Pete Schoening, who pretty much single-handedly save the lives of all the other climbers with his famous emergency belay when Houston slipped and dragged everyone else down (from memory, but it may have been someone other than Houston).

Feel free to mock, but coming from the pen of Charlie Houston, and as a way of describing the bond between the climbers on that particular expedition, I reckon it carries considerable weight.